Geotagging of pages is described at various sites (Geotagging, geo-tag.de, geotags.com, geourl.org). In essence there are two ways (both of which are supported by this plugin) to geotag a page, one using a microformat, the other using meta tags in the page header.
For a blog post on this please see: http://www.geodienstencentrum.nl/blog/webmapping/dokuwiki/2014-07-16/dokuwikispatial_geotag.html
There are various plugins for the most common browsers that will interact with geotagged pages, also seachengines will pick up the geo-information making the page locatable on a map.
Geotagged pages can be validated using the online validator at: http://www.geo-tag.de/validator/en.php